Book contents
- Frontmatter
- Contents
- Participants
- Preface
- Acknowledgements
- Observations of Supernovae and the Cosmic Distance Scale
- Type Ia Supernovae
- Type Ib and Type II Supernovae
- SN 1987A, SN 1993J, and Other Supernovae
- X-Rays and γ-Rays from SN 1987A
- Spectrophotometry of SN 1987A from the Kuiper Airborne Observatory
- Infrared Spectroscopy of SN 1987A
- SN 1987A: Observations at Later Phases
- Freeze out, IR-Catastrophes, and Non-thermal Emission in SNe
- Understanding the Nebular Spectrum of SN 1987A
- The Oxygen 1.13 µm Fluorescence Line of SN 1987A: a Diagnostic for the Ejecta of Hydrogen-Rich Supernovae
- Review of Contributions to the Workshop on SN 1993J
- A Determination of the Properties of the Peculiar SNIa 1991T through Models of its Early-time Spectra
- Supernovae and Circumstellar Matter
- Supernova Remnants
- Catalogues
- List of Contributed Papers
SN 1987A: Observations at Later Phases
from SN 1987A, SN 1993J, and Other Supernovae
Published online by Cambridge University Press: 04 August 2010
- Frontmatter
- Contents
- Participants
- Preface
- Acknowledgements
- Observations of Supernovae and the Cosmic Distance Scale
- Type Ia Supernovae
- Type Ib and Type II Supernovae
- SN 1987A, SN 1993J, and Other Supernovae
- X-Rays and γ-Rays from SN 1987A
- Spectrophotometry of SN 1987A from the Kuiper Airborne Observatory
- Infrared Spectroscopy of SN 1987A
- SN 1987A: Observations at Later Phases
- Freeze out, IR-Catastrophes, and Non-thermal Emission in SNe
- Understanding the Nebular Spectrum of SN 1987A
- The Oxygen 1.13 µm Fluorescence Line of SN 1987A: a Diagnostic for the Ejecta of Hydrogen-Rich Supernovae
- Review of Contributions to the Workshop on SN 1993J
- A Determination of the Properties of the Peculiar SNIa 1991T through Models of its Early-time Spectra
- Supernovae and Circumstellar Matter
- Supernova Remnants
- Catalogues
- List of Contributed Papers
Summary
The last observations (until April 1993) of SN 1987A made at ESO, La Silla, are presented. Our data show that: (i) the criterion of line shifts proves that dust is still present and is absorbing more strongly than ever; (ii) the I magnitude decreases faster than the other ones after day ∼1700; (iii) the 1.3mm flux is constant at about 9mJy, and comes most probably from free-free emission produced by the cooling of the former star envelope still weakly ionized. Previous analyses of the bolometric light curve until day 1444 are briefly reviewed. In spite of the large uncertainties, the flattening of the light curve, observed after day ∼900, extends until our latest data points (day 2172). This can be explained by theoretical models including time-dependent effects due to long recombination and cooling times (Fransson and Kozma 1993). However, one cannot rule out the presence of a compact object such as a neutron star, radiating as a pulsar or accreting matter from a disk either continuously or intermittently.
The Dust
In order to understand many aspects of the observed behaviour of SN 1987A at later phases, one must appreciate the role of dust in the expanding ejecta of the supernova. Molecules such as CO and SiO were formed at a very early phase (<100 days after outburst) (Bouchet and Danziger 1993). Probably as a result of the presence of molecules, dust formed at approximately day 530 and has since continued to play a dominant role in absorbing much of the harder radiation and thermalizing it.
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- Supernovae and Supernova RemnantsIAU Colloquium 145, pp. 201 - 210Publisher: Cambridge University PressPrint publication year: 1996
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